1. Field of the Invention
This invention relates generally to keyboard assemblies, and more particularly to a flat keyboard assembly which does not incorporate individual switch-actuating push-buttons.
2. Description of the Prior Art
Keyboard switch assemblies of the type utilized with electronic calculators and for digital control of appliances such as micro-wave ovens and television receivers, conventionally comprise a printed circuit board having a plurality of resilient dome switch elements thereon respectively actuated by individual push-buttons. U.S. Pat. No. 3,796,843, assigned to the assignee of the present application, discloses a keyboard switch assembly in which all of the conductors forming an X-Y switch matrix are disposed on one side of the printed circuit board, the switch elements being triangular shaped so that certain conductors may extend under the switch elements. It has been proposed to provide a flat keyboard assembly in which the push-buttons are replaced by a relatively thin, flexible member having one side in facing relationship with the switch elements so that deflection of the member in a particular area in response to force manually exerted on the other side of the member actuates a respective switch element, the other side of the member having keyboard indicia thereon; however, in such prior flat keyboard assemblies known to the present applicant, force exerted at a particular indicia on the flat keyboard member has not been sufficiently isolated from switch elements aligned with other indicia so that actuation of switch elements in addition to the intended switch element may result. It is therefore desirable to provide a flat keyboard assembly wherein erroneous actuation of switch elements is inhibited.